Push-button switch control station



March 6, 1945- c. F. IROBBINS PUSHBUTTON SWITCH CONTROL STATION 2Sheets-Sheet 1 Filed Feb. 17, 1944 March 6, 1945. c. F. ROBBINS vPUSHBUTTON SWITCH CONTROL STATION Filed Feb. 17,. 1944 2 Sheets-Sheet 2Patented Mar. 6, 1945 PUSH-BUTTON SWITCH CONTROL STATION Clyde F.Robbins, Milwaukee, Wis., assignor to Cutler-Hammer, Inc., Milwaukee,Wis, a corporation of Delaware Application February 17, 1944, Serial No.522,724

13 Claims.

This invention relates to improvements in pushbutton switch controlstations.

A primary object of the invention is to provide novel and simple meansfor enabling locking of the pushbutton switch in a'position to interrupta circuit controlled thereby.

Another object is to provide means of the aforementioned character whichinsures movement of the pushbutton, automatically if necessary, to suchcircuit interrupting position as an incident to the locking operation.

Another object is to provide for such locking by means or" a padlock ofany well known form.

Another object is to improve and simplify the construction and assemblyof the parts of sheet emetal enclosing casings for pushbutton switches.

Another object is to minimize the number of different parts required toform such sheet metal casings, and to utilize one part thereof forsupport of the locking elements.

Various other objects and advantages of the invention will hereinafterappear.

The accompanying drawings illustrate a preferred form of the inventionwhich will now be described; it being understood that the embodimentillustrated is susceptible of modification in respect of certainstructural details thereof within the scope of the appended claims.

In the drawings,

Figure 1 is a front elevational view of a fragment of a sheet metalenclosing casing within which the pushbutton switch mechanism is housed;the pushbutton being in its outerv extreme position, to which it isnormally springbiased. a portion of the operating cam ring cooperatingwith a suitable legend to indicate a circuit completing position of theswitch, and the pushbutton locking means being shown in its normalinoperative position. i

Fig. 2 is a view similar to Fig. 1, but showing the cam ring rotated toits safe or circuit interrupting position, and with the locking devicein a position to prevent reverse rotation of the cam ring upon properassociation of a padlock hasp with respect thereto.

Fig. 3 is a fragmentary section, on the line 33 of Fig- 1.

Fig. 4 is a sectional view, on the line 4-4 of Fig. 2, and

Fig. 5 is a fragmentary sectional view, on the line 5-5 of Fig. 1, andshowing in elevation the other end portion of the casing.

The pushbutton switch herein disclosed is of Y the plural position,rotary selector type disclosed in my prior application, Serial No.451,417, filed July 18, 1942; with particular reference to Figs. 6, '7,and 8 of the drawings of said application. Thus the switch as showncomprises a one-piece molded insulating base H) which is recessed toslidably accommodate a one-piece molded insulating plunger H. Plunger His shown as provided with two pairs of bridging contactors [2 (Figs. 4and 5); the contactors of each pair being normally spring-biased apart,as shown in Fig. 4; and the space between the contactors of each pairbeing taken up when plunger H is in its upper extreme position, to whichit is biased by a coiled compression spring, as shown at is in Fig. 5,or when the plunger H is depressed to its lower extreme position, ashereinafter described.

' The contact tips upon the upper bridging contactors are adapted toengage pairs of contact tips 14 upon upper sets of stationary contactswhen plunger 1 1' is free to move upwardly under its spring bias, asshown in Fig. 5; and the contact tips upon the lower bridging contactorsare adapted to engage corresponding pairs of contact tips 14 upon lowersets of stationary contacts, in the event that plunger H is depressed toits lower extreme position. As illustrated in Fig. 4, plunger H isadapted to be depressed to and retained in an intermediate positionthereof wherein all of the bridging contactors l2 are disengaged fromthe associated sets of stationary contacts, this being the so-called"safe, or circuit interrupting position of the switch mechanism.

Morespecifically, the plunger l I has removably fitted to the upper endor extension thereof a molded insulating pushbutton I5 which is shown inits upper extreme position to which it is normally biased by the actionof spring I3 upon plunger ll; thus providing for engagement of the upperbridging contactors with their associated sets of upper stationarycontacts, as shown in Fig. 5. In Fig. 4, pushbutton I5 is shown in anintermediate, or partially depressed position wherein all of thebridging contactors are disengaged from their associated; stationarycontacts. Such normal and/or intermediate positioning of pushbutton I5is preferably effected by employment of a ring-type rotary cam member l6(Fig. 40. which surrounds said pushbutton.

Member 16 is provided with two diametrically opposite-sets of downwardlyfacing cam surfaces,

'one set of which,surfaces is shown at I! and. I8,

v The corresponding cam surfaces of said sets are adapted forsimultaneous cooperative engage-'-' ment with diametrically oppositeintegral laterally or radially projecting lugs upon pushbutton l5; oneof said lugs being shown at IS in Fig. 4. Thus when lugs iii are engagedwith the upper end portions of cam surfaces l8 the pushbutton l5 will berestrained against upward movement from the intermediate positionthereof shown in Fig. 4. Manual rotation of ring l6 from each extremeposition thereof to the other is facilitated by providing thereonintegral upstanding lugs 20 and 2!, which are preferably arranged indiametrically opposite relationship to each other.

As shown in Fig. 1 the sheet metal enclosing casing for the pushbuttonswitch mechanism is provided in its cover member 22 with a circularopening 23 which affords clearance for ring it and its lugs 2E3 and 25during rotation thereof from each extreme position to the other. Covermember 22 also preferably has rigidly attached to the outer surfacethereof a substantially annular flat plate 25 upon which suitablelegends may be applied, which legends may be Safe, Stop, and On,arranged as shown in Figs. 1 and 2. Thus withthe switch parts in therelative positions thereof shown in Fig. 4-, the lug 2@ will be radiallyalinedwith the legend Safe (Fig. 2) to indicate interruption of all ofthe circuits to be controlled by the switch.

On the other hand, upon counterclockwise rotation of ring I6 from theextreme position thereof shown in Fig. 2 to the extreme position thereofshown in Fig. l. the lug 2i thereon will be radially alined with thelegend On to indicate the normal circuit completing relationship of theswitch parts shown in Fig. 5. In such position of the switch parts thelugs I9 (see Fig. 4) are freed to move under the aforementioned bias ofspring [3 to the upper ends of the pair of cam surfaces, one of which isshown at I]. The plate 24 is preferably provided with a diametricallyopposed pair of inwardly extending integral radial lugs 25 and 26 whichlie in the rotary path of lugs 20 and 2| to positively limit the degreeof rotary movement of ring l6 iii-each direction. In practice, however,such rotary movement of ring IS in each direction ispositively limitedby cooperation of elements carried thereby with parts carried by theadapter member 26; said adapter member 26 and insulating base l beingrigidly attached to each other and to the bottom wall 21 of the sheetmetal enclosing cas- 'for depression thereof toward or to its lowerex-vtreme position; by a thumb or finger of an operator, whether ring I6 isin one extreme position 'or the other. With the particular multiplecircuit controlling switch mechanism herein illustrated such depressionof pushbutton lto its lower extreme position is adapted toprovide forcompletion of an alternative circuit for effecting stopping of atranslating device controlled by the switch. However, in those cases inwhich it is desirable to lock the switch mechanism in its ance with myinvention all of the aforementioned .desirable results are attained bythe employment of a simple form of combined operatinglock-v ing andprotecting device, which will now be described.

Said device comprises a punched and stamped sheet metal member having afiat portion 29 pivota-lly supported in upwardly spaced parallelrelationship to the front face of the cover member 22, as by means of apin 35?. Thus, as best illustrated in Fig. 3, pin 3% is provided with acylindrical shank portion 39 against which the'cir-v cular wall of anopening 32 in said flat portion 29 is adapted to bear. A pair of flatwashers 33 and 34 are positioned upon opposite sides of portion 29, anda resilient dished washer 35 is interposed between washer 35. and theouter face of cover member 22. Pin till is provided with a reducedcylindrical shank portion 36 which penetrates an opening 3'1! in covermember 22, the lower end of said shank portion 36 being upset over theinner face of cover member 22 to retain said parts in assembledrelation.

Assuming-vertical mounting of the enclosing r casing, as shown in Fig.1, said sheet metal member will be biased by gravity to a positionwherein an edge 38 of the flat portion 29 abuts against thehemispherical head of one of a pair of screws 39 which areemployed tohold the cover and base portions of the casing in assembled relation, ashereinafter more fully described. In such position of portion 29 ring l6may be moved from each extreme position thereof to the other withoutinterference. However, with ring 16 in the rotary position thereof shownin Fig. 1, upon pivotal movement of fiat portion 29 in a clockwisedirection a cam-like edge portion 40 thereof is adapted to engage theadjacent edge portion of lug 20 of ring l5 to efi'ect correspondingclockwiserotation of the latter to provide for Safe positioning of theswitch parts, as

aforedescribed, and as illustrated in Figs. 2 and 4.

When said flat portion 29 is in the position thereof shown in Fig. 2 thematerial thereof between said edge 40 and an edge 42 is adapted tofairly completely overlie the upper end of push-- button I5, wherebyaccess to the latter by a thumb or finger of the operator is positivelyprevented. As best illustrated in Fig. 2 the edge 42 is so shaped as toavoid interference thereof 'with the side edge 43 of lug 2|.

1 Said flat portion 29 is provided with an extension 44, and extendingupwardly at substantially a right angle to the latter is an arm or lug45 having a substantially circular opening 46 formed therein (Figs. 4and 5). Lug 45 thus serves as a handle to facilitate manual pivotal"Safe position it is undesirable to permit the operator to complete theStop'-' circuit pending unlocking of ,the switch mechanism. 0n the otherhand, if the switch mechanism is unlocked its lower extreme position isdesired. In accordmovement offlat portion 29 in a clockwise directionfrom the position thereof shown in Fi 1.

A punched and stamped sheet metal lug member has a flat portion 41extending upwardly through an opening of substantially correspondingcross sectional shape in the forward wall of cover member 22, said lugmember having an intermediate bend or offset 48 below said forward wall,and'a second flat portion 49 (Fig. 4) spot welded or otherwise rigidlyand permanently se cured to the inner surface of one of the two sidewalls of the casing which are formed in-' tegrally with cover member 22.Flat portion 41 is so arranged as to be closely adjacent to and parallelwith the aforementioned lug 45 upoh clockwise movement of flat portion29 to the exof a size corresponding to and alined with the opening 46 inlug 45. The hasp 51 (Figs. 2 and 4) of a padlock 52 may be insertedthrough said openings 46 and 50 and then locked in the usual manner toinsure the relative positioning of the various parts as shown in Fig. 2,pending unlocking and removal of the padlock hasp.

With further reference to Fig. 2, it will be apparent that the ring maybe rotated to the position thereof illustrated by direct manualengagement with one or both of the lugs and 21; the flat portion 29being thereafter moved to the position illustrated in Fig. 2 to permitlocking of the parts in the manner aforedescribed.

It will also be noted with respect to Fig. 2 that upon unlocking of lugwith respect tolug 41 and counterclockwise movement of flat portion 29to the normal position thereof shown in Fig. l, the switch mechanismwill remain in its Safe position, with the electrical circuit open. Theadded operation of requiring the ring I6 to be manually rotated in acounterclockwise direction to effect On positioning of the switch partsis an intended safety feature to compel the operator to perform twooperations, thus insuring con sideration by the operator of the questionof whether or not the equipment can safely again be put intoservice.

As aforestated the base portion of the sheet metal casing includes amember of the desired length which forms the bottom wall 21 (Figs. 4 and5); said member being of relatively shallow channelshape in transversecross section, the substantiallyparallel upstanding side flanges thereofbeing designated by numerals 53 and 54, and said flanges extendingthroughout the length of bottom wall 21. In practice said casings aremade in different lengths, to accommodate from one (as shown) to eightpushbutton switch mechanisms. When two or more pushbutton switchmechanisms are housed within a casing, the lower or end unit will havemy improved locking device applied thereto, as shown, whereas the otherunits will ordinarily not be of the locking type. Upon selection'of thedesired length of the member forming bottom plate 21, the same will haveassociated with opposite ends thereof a pair of like end walls 55, 55formed of sheet metal of approximately the same thickness as bottom wall21. v 7

End walls 55. are provided with relatively short peripheral flanges 56extending inwardly at substantially right angles thereto, the bottomportion of each such flange having an inward extension located in theplane thereof, as shown at 51; said bottom portion of flange 56 andextension 51 underlying bottom plate 21 as shown in Figs. 4 and 5.Extensions 51 have openings 58 formed therein, as shown in Fig. 5, andbottom plate 21 has relatively smaller openings alined there- 66, torespectively accommodate the flanges 53 and 54 of bottom plate 21. Saidoffsets 65 and66 are spot-welded to the respective flanges 53 and 54 ata plurality of points, as indicated at m in Fig. 5. Also as indicated atfour points marked a: in Fig. 4, each inner member 60 is spot-welded tothe inner surface of the end wall 55 associated therewith. In thismanner the end walls 55 are rigidly and permanently attached to thebottom plate 21.

Each'inner sheet metal member 611 has spot- .weldedv at a plurality ofpoints to its top flange 6|, at the midpoint thereof, a relatively thicksheet metal member 61 having a tapped opening formed therein, wherebysuch member 61 acts as a nut for cooperation with the shank of one ofthe aforementioned cover-securing bolts 39. The'end walls 55 areprovided with suitable multiple knockouts 68 (Fig. 5), the respectiveinner sheet metal members 66 having openings or cut away portions 60*,as shown at the left hand side of Fig. 5, of greater dimensions thansaid knockouts.

The cover member 22 has a specially formed top wall, as best illustratedin Figs. 1, 2, and l, and the top fianges'of end walls 55 are shaped toconform thereto (see Figs. 1 and 2). Cover member 22 has side walls 69and 18 formed integrally therewith and extending downwardly in parallelrelationship to each other throughout substantially the entire depth ofthe casing, as best illustrated in Fig. 4.

The cover member 22 is assembled by a straightline sliding movementdownwardly over the base portion of the casing to a position flush withthe end wall flanges 55, as shown in Figs. 1, 2 and 5, whereupon thecover may be secured in position by the screws or bolts 35aforementioned. As will be understood, the cover member 22 will have oneor more openings formed therein to accommodate the pushbuttons of theparticular number of switch units housed by the casing. Also as shown at1| in Figs. 1, 2, and 5, and at 12 in Fig. 5. the front wall of thecover member 22 may be suitably ornamented to improve the appearancethereof, in conjunction with the aforementioned special form thereof intransverse cross section.

I claim':

1. In an electric switch device, in combination, a sheet metal casingadapted for vertical mounting, a switch mechanism housed thereby,

said mechanism including'an operating member with as shown at 59, theopenings 59 being adapted to accommodate. the shanks of bolts or widththan the peripheral flanges 56 of end walls 7 5 5, as best'illustratedat the left hand side of Fig. 5. Moreover, the lower portions ofsaidside flanges 62 and 63 are extended inwardly a substantial distance,as'shown at 64 in Fig. 5. and said lower portions areoflset as shown at65 and in the form of a pushbuttcn,-said casing having an opening formedin the front wall thereof to afford clearance for said pushbutton, saidpushbutton being spring biased to a forward extreme position thereof toprovide for completion of a controlled circuit, a ring type rotary camsurrounding said pushbutton and adapted in one extreme position of theformer to permit forward movement of said pushbutton to the biasedposition thereof, said cam ring in its other extreme position beingadapted to effect depression of said pushbutton to effect interruptionof said controlled circuit, a pair of outwardly extending lugs formedintegrally with said ring in predetermined relationship to the camsurfaces thereon to facilitate manual rotation of said ring from eachextreme position thereof to the other, a sheet metal member pivotallysupported upon the outer surface of said casing adjacent said pushbuttonopening in the latter but normally biased to a position out of alinementwith said opening, said sheet metal member including a flat portion onethereof to act as a cam for cooperation with one of said lugs to insuremovement of said ring to its second mentioned extreme positionwherebyinterruption of the circuit controlled by said pushbutton is effected,said sheet metal member having a perforated lug portion upstandingtherefrom to facilitate manual movement thereof, and

a second perforated lug upstanding from said casing, the perforations insaid last mentioned lugs being closely adjacent and alined with eachother upon completion of such pivotal movement of said sheet metalmember to provide for insertion of a padlock hasp whereby said parts maybe locked in their last mentioned positions.

2. In an electric switch device, in combination, a sheet metal casingadapted for vertical mounting, a switch mechanism housed thereby, saidmechanism including an operating member in the" form of a pushbutton,said casing having an opening formed in the front wall thereof to affordclearance for said pushbutton, said pushbutton being spring biased to aforward extreme position thereof to provide for completion of acontrolled circuit, a ring type rotary cam surrounding said pushbuttonand adapted in one extreme position of the former to permit forwardmovement of said pushbutton to the biased position thereof, said camring in its other extreme posi tion being adapted to effect depressionof said pushbutton to effect interruption of said controlled circuit, apair of outwardly extending lugs formed integrally with said ring inpredetermined relationship to the cam surfaces thereon to facilitatemanual rotation of said ring from one of said lugs to insure movement ofsaid ring to its second mentioned extreme position whereby interruptionof the circuit controlled by said push: button is eifected, said sheetmetal member having a perforated lug portion upstanding therefrom tofacilitate manual movement thereof, a second perforated lug upstandingfrom said casing, the perforations in said last mentioned lugs beingclosely adjacent and alined with each other upon completion of suchpivotal movement of said sheet metal member to provide for insertion ofa padlock hasp whereby said parts may be locked in their last mentionedpositions, and the cam edge of said fiat portion of said sheet metalmember having an adjacent part shaped to di rectly overlie thepushbutton opening in'said cas ing under saidconditions whereby directmanual engagement of said pushbuttonfor further dey pression thereof ispositively prevented,

3. In an electric switch device, in combination, a sheetmetal casingadapted for vertical mounting,' a switchmechanism housed thereby, saidmechanism including an operating member in the tion being adapted toeilect depression of said pushbutton to effect interruption of saidcontrolled circuit, a pair of outwardly extending lugs formed integrallywith said ring in predetermined relationship to the cam surfaces thereonto facilitate manual rotation of said ring from each extreme positionthereof to theother, a sheet metal member pivotally supported upon theouter surface of said casing adjacent said pushbutton opening in thelatter but normally biased to a position out of alinement with saidopeningsaid sheet metal member including a, flat portion one edge ofwhich is adapted upon pivotal movement thereof to act as a cam forcooperation with one of said lugs to insure movement of said ring to itssecond mentioned extreme position whereby interruption of the circuitcontrolled by said pushbuttonis effected, said sheet metal member havinga perforated lug portion upstanding therefrom toifacilitate manualmovement thereof, a second perforated lug upstanding from said casing,the perforations in said last mentioned lugs being closely adjacent andalined with'each other upon completion of such pivotal movement of saidsheet metal member to provide for insertion of a padlock ha'sp wherebysaid parts may be locked in their last mentioned positions, the cam edgeof said flat portion of said sheet metal memher having an adjacent partshaped to directly overlie the pushbutton opening in said casing undersaid conditions whereby direct manual eng'agement of said pushbutton forfurther depression thereof is positively prevented, and said sheet metalmember when in its normally biased being adapted for straight-linesliding movement into engagement with flanges upon the bottom and endwalls of said base portion, a pushbutton ,switch mechanism including aninsulating base member secured to said bottom wall of the casing, saidcoverv portion having an opening formed in the top wall thereof, saidmechanism including a pushbutton normally biased outwardly to acircuit-completing position and movable by direct manual engagement outof said position, a cam ring associated with'said pushbutton and having4 limited rotary movement between opposite extreme positions, said ringhaving peripherally spaced lugs upstanding therefrom to' facilitatemanual movement thereof, said ring'in one ex-- treme position thereofpermitting movement of other extreme position being adapted to effectform of a pushbutton, said casing having an opening formed in thefrontwall thereof to afford -fclea'rance for saidpushbuttbn, said pushbuttonbeing spring biased to a forward extreme position thereof to provide forcompletion of a con-' trolled circuit, a ring type rotary camsurrounding said pushbutton and adapted in one extreme position of theformer to permit forward-movemovement of said pushbutton out of saidcircuitcompleting position, a punched and stamped sheet metal cam memberpivotally supported upon the top wall of said cover portion, said camment of said pushbutton from said circuit-completing position" thereof,and said cam member in said extreme position thereof being adapted tooverlie said pushbutton to effectively prevent direct' manual engagementwith the latter, for the purpose set forth.

5. In an electric pushbutton switch station, in combination, a metalcasing including a base portion forming the bottom and end walls thereofand an inverted U-shaped cover portion forming the top and side wallsthereof, said cover portion being adapted for straight-line slidingmovement into engagement with flanges upon the bottom and end walls ofsaid base portion, a pushbutton switch mechanism including an insulatingbase member secured to said bottom wall of the casing, said coverportion having an opening formed in the top wall thereof, said mechanismincluding a pushbutton normally biased outwardly to a circuit-completingposition and movable by direct manual engagement out of said position, acam ring associated with said pushbutton and having limited rotarymovement between opposite extreme positions, said, ring havingperipherally spaced lugs upstanding therefrom to facilitate manualmovement thereof, said ring in one extreme position thereof permittingmovement of said pushbutton to its nor- ;mally biased circuit-completingposition, said ring when moved-to its other extreme position beingadapted to effect movement of said pushbutton out of saidcircuit-completing position, a punched and stamped sheet metal cammember pivotally supported upon the top wall of said cover portion, saidcam member being manually movable toward one extreme position thereofwhereby it is adapted to cooperate with one of said lugs to insuremovement of said pushbutton from said circuit-completing positionthereof, said cam member in said extreme position thereof being adaptedto overlie said pushbutton to effectively prevent direct manualengagement with the latter, forthepurpose' set forth,'a pair ofperforated lugs upstanding respectively from the top wall of said coverportion and from said cam member, and said lugs being positioned closelyadjacent each other with their perforations in alinement in said extremeposition of the cam member, whereby a padlock hasp may penetrate saidperforations to provide for locking of said cam member in said extremeposition.

. 6. In combination, a switch including a push button normally biasedoutwardly to an on position to provide for completion of a controlledcircuit, a rotatable ring type cam surrounding the upper end portion ofsaid pushbutton, said cam-having a pair of diametrically opposedupstanding lugs to facilitate manual rotation thereof, means associatedwith said lugs to limit rotation of said cam between extreme positions,said cam in one of its extreme positions permitting movement of saidpushbutton to its bi-' ased position, said cam when moved to its otherextreme position being adapted to simultaneously efiect movement of saidpushbutton to a posi tion wherein the controlled circuit is interrupted,said pushbutton in the last mentioned position button normally biasedoutwardly to an on position to provide for completion of a controlledcircuit, a rotatable ring type cam surrounding the upper end portion ofsaid pushbutton, said cam having a pair of diametrically opposedupstanding lugs to facilitate manual rotation thereof, means associatedwith said lugs to limit rotation' of said cam between'extreme positions,said cam in one of its extreme positions permitting movement of saidpushbutton to its biased position, said cam when moved to its otherextreme position being adapted to simultaneously effect movement of saidpushbutton to a position wherein the controlled circuit is interrupted,said pushbutton in the last mentioned position thereof being normallydepressible by direct manual engagement to a third position to providefor completion of an alternative circuit, a cam member pivotallysupported adjacent said first mentioned cam and normally biased to aninoperative position, said cam member having an edge portion adapted fordriving engagement with one of said lugs upon pivotal movement of theformer to an extreme position thereof to effect movement of said firstmentioned cam to its second mentioned extreme position, said cam memberhaving a portion adjacent said edge portion thereof adapted to overliesaid pushbutton to insure against direct manual engagement with thelatter in the aforementioned extreme position of the former, said ca'mmember having a lug upstanding therefrom to facilitate manual pivotal 1movement thereof, a relatively fixed lug with respect to which said lastmentioned lug is adapted 8. In a pushbutton switch station, incombi-.nation, a sheet metal housing comprising a base thereof being normallydepressible by direct man-I- ual engagement to a third position toprovide for completion of an alternative circuit, a cam member pivotallysupported adjacent said first men- 'tioned cam and normally biased to aninoperative position, said cam member having an-edge portion adapted fordriving engagement with one of said lugs upon pivotal movement of theformer to an extreme position thereof to effect movement of said firstmentioned cam to its second mentioned extreme position, and said cammeniber having a portion adjacent said edge portio thereof adapted tooverlie said pushbutton to insure against direct manual engagement withthe to move, and said last mentioned lugs having openings formed thereinto provide-for insertion of a locking element jointly therethrough whenalined in, said extreme position of said member.

portion and a cover portion, said base portion including a bottom plateof relatively shallow channel form in transverse cross section, a pairof end members of like form rigidly and permanently secured to saidbottom plate, each of said end members comprising an outer plate ofrelatively heavy sheet metal havin an inwardly extending peripheralflange and an inner plate of relatively thin'sheet metal, said innerplate being arranged in nested relation to said outer plate and havingflanges formedat the top and sides thereof extending inwardly to agreater extent than said flange first mentioned, the bottom portions ofthe side flanges of said inner plate being spot-welded at a plurality ofpoints to the respective inner surfaces of the bottom plate flanges,each of said outer plates being also spot- -welded at'a plurality ofpoints to the inner plate verted U-shape in transverse cross section,said cover member being adapted for positioning by a straight-linesliding movement into a substantially flush relation to the top and sideportions of the peripheral flanges of said outer plates,and

means associated with the top flange portions of said inner plates andwithsaid cover member to accommodate securing screws whereby said covermember is retained in proper position.

9. In a pushbutton switch station, in combination, a sheet metal housingcomprising a base portion and a cover portion, said base portionineluding a bottom plate of relatively shallow channel form intransverse cross section, a pair of I ;the side flanges of said innerplate being spot-- welded at a plurality of points to the respectivefiinner surfaces of the bottom plate flanges, each of said outer platesbeing also spot-welded at a plurality of points to the inner plateassociated therewith, a punched and stamped sheet metal cover member ofsubstantially inverted U-shape' in transverse cross section, said covermember being adapted for positioning by a straight-line sliding movementinto a substantially flush relation tothe top and side portions of theperipheral flanges ofsaid outer plates, means associated with the topflange portions of said inner plates and with said cover member toaccommodate securing screws whereby said cover member is retained inproper position,"at least one switch mechanism including an insulatingbase rigidly secured to said bottom plate, said mechanism including apush-button, and said, cover member having an opening formed in theforward wall thereof to provide reciprocating clearance for saidpush-button.

10. In a pushbutton switch station, in combination, a sheet metalhousing comprising a base portion and a cover portion, said base portionincluding a bottom plate of relatiyely shallow channel form intransverse cross section, a pair ofend members of like form rigidlyandpermanently secured to'said bottom plate, each of said end memberscomprising an outer plate of rela- 2tively heavy sheet metal having aninwardly extending peripheral flange and .an inner plate of relativelythin sheet metal, said inner plate being arranged in nested relation tosaid outer plate and having flanges formed at the top and sides thereofextending inwardly to a greater extent than said flange first mentioned,the bottom p rtions of the side flanges of said inner plate beingspot-welded at a plurality of points to the respective inner surfaces ofthe bottom plate flanges, each of said outer plates being alsospot-welded at a plurality/of points to the inner plate associatedtherewith, a punched and stamped sheet metal cover member 'ofsubstantially inverted U- shape in transverse cross section, said covermemher being, adapted for positioning by a straightline sliding movementinto a substantially flush relation to the top and side portions of thepe-' ripheral flanges of said outer plates, means associated with thetop flange portions of said inner plates and with said cover member toaccommodate securing screws whereby said cover member is retained inproper position, at least one switch I mechanism including an insulatingbase rigidly channel form in transverse cross section, a pair of endmembers of like form rigidly and permanently secured to said bottomplate, each of said endmembers comprising an outer plate of relativelyheavy sheet metal having an inwardly extending peripheral flange and aninner plate of relatively thin sheet metal, said inner plate beingarranged in nested relation to said outer plate and having flangesformed at the top and sides thereof extending inwardly to a greaterextent than said flange first mentioned, the bottom portions of the sideflanges of saidinner plate being spot-welded at a plurality of points tothe respective inner surfaces of the bottom plate flanges, each of saidouter plates being also spotwelded at a plurality of points to the innerplate associated therewith, a punched and stamped sheet metal covermember of substantially inverted U-shape in transverse cross section,said cover member being adapted for positioning by a straight-linesliding movement into a substantially flush relation to the top and sideportions of the peripheral flanges of said outer plates,

means associated with the top fiangeportions of said inner plates andwith said cover member to accommodate securing screws whereby said covermember is retained in propr position, at least one switch mechanismincluding an insulating base rigidly secured to said bottom plate, saidmechanism including a push'button, .said cover member having an openingformed in the forward. wall thereof to provide reciprocating clearancefor said pushbutton, a ring-type rotary secured to said bottom plate,said mechanism,

includinga pushbutton, said'cover member hav-' ing an opening formed inthe forward wall thereof to provide reciprocating clearance for said'pushbutton, a ring-type rotary cam member car ried by said switchmechanism, said cam member having peripherally spaced lugs upstandingtherefrom to facilitate manipulation thereof. and said cover openingbeing shaped to aflord clean cam member carried by said switchmechanism,

said cam member having peripherally spaced lugs upstanding therefrom tofacilitate manipulation thereof, said cover opening being shaped toafford clearance for said lugs and to limit the range of rotary.movement thereof, a perforated sheet metal lug secured to said covermember and upstanding therefrom, a punched and stamped sheet metalmember having a flat portion pivotber having a perforated lug upstandingfrom said flat portion thereof, and the perforations in said lastmentioned lug and said cover lug being aimed and closely adjacent eachother in said given positionof said cam member, whereb a" padlock haspmaybe inserted therethroughjoint- 'ly for locking sitions.

of the parts in their respective po- 12. In combination, an electricswitch com-' prising a recessed molded insulating base having aninsulating plungerslidable within the retacts,--a pushbutton carried bysaid plunger at the outer end thereof, a ring-type cam surrounding saidpushbutton, said cam in'one rotary position thereof providing foroutward movement of said plunger to its normally biased position. to

2,370,377 I provide for engagement of said contactorwith end thereof, aring-typ cam surrounding said said contacts, said cam in another rotaryposipushbutton, said can in one rotary position tion thereof beingadapted to effect and mainthereof providing for outward movement of saidtain disengagement of said contactor from said plunger to its normallybiased position to procontacts, the upper end of said pushbutton being 5vide for engagement of said contactor with said accessible for directmanual engagement in contacts, said cam in another rotary positioneither of said rotary positions of said cam, a thereof being adapted toeffectand maintain discasing in which said switch is mounted, saidengagement of said contactor from said contacts,

casing having an opening formed therein to prothe upper end of saidpushbutton being accessible vide operating clearance for said pushbuttonand 10 for direct manual engagement in either of said said cam, said camhaving a plurality of periphrotary positions of said cam, said casinghaving erally spaced lugs upstanding therefrom .subv an opening formedtherein to provide operating stantially beyond said casing to facilitatemanclearance for said pushbutton and said cam, said ual rotationthereof, said casing having a percam having a plurality of peripherallyspaced forated lug member attached-thereto andup- 15 lugs upstandingtherefrom substantially beyond standing therefrom at one side of saidopening, said casing to facilitate manual rotation thereof, a relativelythin cam member pivotally supported said casing having a perforated lugmember at by the upper surface of said casing in parallel tached theretoand upstanding therefrom at one relationship thereto, said cam memberhaving side of said opening, a relatively thin cam meman edge portionadapted to cooperatively engage 2o ber pivotally supported by the uppersurface of one of said first mentioned lugs upon pivotal said casing inparallel relationship thereto, said movement of the former in onedirection to effect cam member having an edge portion adapted to apredetermined degree of rotary movement of cooperatively engage one ofsaid first mentioned said first mentioned cam, and said cam member lugsupon pivotal movement of the former in one having a perforated lugupstanding therefrom direction to effect a predetermined degree of mforparallel alinement with said first mentioned tary movement, of saidfirst mentioned cam, perforated lug under such conditions, whereby a cammember having a perforated lug upstanding padlock hasp may be passedthrough said perfotherefrom for parallel alinement with said first ratedlugs Jointly for locking the switch and cam mentioned perforated lugunder such conditions, in their respective positions. whereby a padlockhasp may be passed through 13. In combination, an electric switchcomprissaid perforated lugs jointly for locking the switch ing arecessed molded insulating base having an and cam parts in theirrespective positions, and insulating plunger slidable within the recess,at said cam member having a Portion adjacent aid ieast one set ofstationary contacts carried by edge thereof adapted to overlie the upperend said base and a bridging contactor carried by of said pushbuttonunder.such conditions. to said plunger, said plunger being biasedoutwardthereby positively prevent direct engagementof yjfrom saidrecessto normally provide for ensaid pushbutton manually. I

gagement of said contactor with said contacts,

a pushbutton carried by said plunger at the outer CLYDE F. ROBBINS.

